Problem in Analysis of RC Building with Infill Steel Plates

[cvatansever]

Hi Everybody,

We are trying to analyze a RC building strengthened by infill plates in both directions. Infill plates are modeled by tension-only strips whose material model is hysteretic material model which is not symmetric in compression and tension. RC elements represented by nonlinearbeamcolumn element with fiber sections are using Concrete01 (unconfined) and Steel01 material models.
All elastic analyses like eigen value work properly. But, in nonlinear analysis we are facing the following lines:

ForceBeamColumn3d::update<>--could not invert flexibility

what is the meaning of these lines exactly and how to overcome this problem ?

Thanks in Advance,

Cuneyt,